Fine mesh screen box



Oct.

31, 1933. E. c. BERGHOEFER EINE MESH SCREEN Box Filed May 29, 1931 www..

lNvENToR Edward BY his ATTQRNEYJ S C- B oder.

latinmail oct. 31, 1933 FINE MESH SCREEN BOX Edward C. Berghoefen Los Angeles, Galli., as-

signer to Link-Belt Company, Chicago,

corporation of Illinois Ill.,a

Application May 29, 1931. Serial No. 540,859

3 Claims.

This invention relates to improvements Vin vibrating screen boxes, particularly with regard to the method of supporting the screen.

'Ihe general object of this invention is to pro- 5 vide an improved screen box structure in which ne mesh screen cloth is supported and secured in place in a manner to insure a minimum wear on the screen cloth with the resultantv increase in its life.

Within the general object of the invention it is a purpose to employ resilient contact or supporting members between the screen cloth and the transverse supports of the screen, box.

A still further object of this invention is to employ tubular rubber members against which the screen cloth contacts.

f Another object of this invention involves the use of such a Contact member for the purpose of preventing the liquid following along the undersurface of the cloth when wet materialsr are being screened.

These and many other objects as will appear from the following detail disclosure are secured by means of this invention.

This invention resides substantially in the combination, construction, relative' location of parts, all as will be set forth in greater detail hereinafter.

Referring to the drawing:

Fig. 1 is a perspective view of a part of the screen box with some of the parts broken away showing the invention applied thereto;

. Fig. 2 is a cross sectional view taken on the line 2-2 of Fig. 1.

The life of ne mesh screen cloth having, for example, 30 meshes to the inch and ner, is a relatively short life when used in vibrating screen boxes. Such a cloth is rather delicate in structure, and as a result has a tendency to rapidlyV wearaway at the points of contact between it and portions of the screen box. This wear occurs particularly at the points where the screen cloth contacts with the transverse members of the screen box which extend underneath the cloth and support it at spaced intervals. The structure of this invention involves the use of a cushioning member, and more particularly members' of rubber which are mounted between the screen and the transverse supporting members. By means of this structure it has been found by actual experience that the life of the clothl is materially lengthened. In addition when wet materials are being screened -such as for example the so-called rotary mud, these cushioning members act as wiperslto remove the arrangement and 12 and 13 which are clamped together at spaced water which runs along the undersurface of the screen.

These and other advantages will appear from the following detail disclosure.

Referring to the drawing a portion of a screen box is illustrated therein. It may be pointed out that the particular construction of the screen box itself is not by itself a particular feature of lthis invention. It will be apparent from the and longitudinally of the box to form the sides i k thereof.

These side channels .1 are united by transverse bars 2, which are shown in the form of angle irons in the illustration. The side members and transverse members are united in any suitable manner, as by bolts, welding, andthe like. Extending along the inner face of each of the, side channels 1 are movable channel members comprising the inclined wall 3 and the substantially right angled anges 4 and 5, all of which are formed from a single plate. These 35 channels, which may be termed cloth tensioning channels are supported adjacent the side channels so that the upper flange 4 fulcrums against the vertical wall of the side channels. The tensioning channels may be moved about their fulcrum and drawn towards the side channels by means of a series of bolts 6 which extend through them and the side channels and cooperate with wing nuts 7. I

Each transverse bar 2 is provided with a hole 95. 8 adjacent each side channel in transverse alignment. A tube of soft rubber 18 is laid upon each transverse member 2 with its ends 9 pulled down through the hole B. The hole 8 is slightly smaller in diameter than the external diameter of the tube 18 so that when the ends are forced into the holes 8 the tubes are clearly held in place as is indicated in Fig. 2. The tubes are restricted at the point of passage through the hole 8 in the region indicated by the reference numeral 10. This effects the securing action described.

The screencloth is shown at` 11, having its side edges clamped between two channel irons members.

intervals by means of the nuts and bolts 14. The ilange 5 and the tensioning channel engages with the channel 13v as indicated, so that as the wing nuts 7 are drawn up the tensioning channels swing towards the side channels to stretch the screen cloth 11 transversely.

It should be noted that no means is shown for tensioning the cloth longitudinally. It is not the usual practice to tension the cloth longitudinally, but of course this may be done without departing from the scope of this invention. Although not shown, it is usual to provide a bar extending longitudinally and centrally of the cloth to which the cloth is secured. This b'ar tends to prevent wiping and is usually clamped down to the screen frame so that the cloth is secured longitudinallyalong its center line.

By this construction it will be seen that when the screen is in action any relative movement between the cloth and the transverse members 2 does not cause wearing of the cloth because of the fact that the tubular members are interposed between the cloth and the transverse By means of this construction it has been found that the life of fine mesh screens is materially lengthened. When wet materials are being scanned such as for example what is known as rotary mud", which is produced from the drilling of oil wells, the resilient members also act as wipers, causing the liquid to run off the undersurface of the screen and prevent it from following along the undersurface of the screen.

The fact that the cushioning members 18.are tubular is of considerable importance. Experi-l ence has shown that solid ruber cushioning i members do not materially increase the life. of

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the screen. The tubular member, however, appears to effect less wearing action on the cloth, so that its life is materially lengthened.

It is emphasized that although the circular form of tube is preferable, hollow resilient tubes of other cross sectional forms may be used to advantage.

From the foregoing description it Will be apparent that this invention resides in certain principles of construction and operation, which of course may be embodiedI by those skilled in the art in other physical forms, and I do not therefore desire to be limited to the disclosure which has been given in an illustrative sense, but rather to the scope of the appended claims.

What l seek to'secure by United States Letters Patent is:

1. A screen box of the type described comprisverse members having apertures therein, ilexible tubular members havingtheir ends secured in the aperture so as to rest upon the transverse members and a screen cloth secured to the frame and resting on the flexible tubular members.V

2. A screen box of the type described comprising a frame made up of side and transverse bottom members secured together, said transverse bottom members having a hole therein adjacent each side member, a resilient tubular member overlying each transverse member with its ends inserted inthe holes, a screen cloth resting on the tubular members, and means for tensioning the screen cloth.

3. A screen box of the type described comprising a frame made up of side and transverse bottom members secured together, said transverse bottom members having a hole therein adjacent each side member, a resilient tubular member overlying each transverse member with its ends inserted in the holes, a. screen cloth resting on the tubular members,. and means for tensioning the screen cloth longitudinally, said holes being of a smaller diameter than the tubular members so as to frictionally secure them in place.

4. In a device as described the combination consisting of a screen box having transverse structural members, a screen cloth secured in said box and resilient tubular members interposed between the screen cloth and transverse structural members in contact therewith, upon which the screen cloth rests, thelongitudinal vaxes of the tubular members lying parallel to the plane of the screen cloth. f

5. In a vibrating screen structure the combination including a screen box having at least one transverse bar, a screen cloth extending betweenrthe sides of the box above the bar and at least one soft resilient tubular member secured i."

between the cloth and the bar upon which the cloth rests throughout the length of the tubular member in tangential relation thereto, the tubular member collapsing and reforming with the movement of the screen when loaded.

6. In apparatus as described a screen support including side members connected by cross bars to form an open bottom frame, a screen cloth positioned above the cross bars, soft resilient hollow members interposed between the cloth and bars so as to contact tangentially throughout the length thereof, and means for securing the cloth and hollow members in the frame in contact with each other, the loaded screen in movement causes the tubular members to collapse and reform so as to mantain contact with the moving screen.

7. In a construction of the type described the combination comprising a frame made up of united longitudinal and transverse members, a screen cloth, means for securing the cloth in said frame to form a screening bottom therefor, and a plurality of soft resilient hollow members interposed between the transverse members and the cloth and extending substantially transversely of the frame in contact with eachother.

8. A screen box having side members united by transverse members', a screen cloth overlying the transverse member, at least one resilient tubular member interposed between the cloth and at least one of the transverse. members, and clamping means for securing the cloth in the box and for clamping the resilient member against the transverse member, whereby the cloth and resilient member are held in contact, the cloth and tubular member being in tangential contact. i l EDWARD C. BERGHOEFER. 

